13.2 Two ways to Execute 80286 Tasks

When porting 80286 programs to the 80386, there are two cases to consider:

Porting an entire 80286 system to the 80386, complete with 80286
operating system, loader, and system builder.

In this case, all tasks will have 80286 TSSs. The 80386 is being used
as a faster 286.

Porting selected 80286 applications to run in an 80386 environment
with an 80386 operating system, loader, and system builder.

In this case, the TSSs used to represent 80286 tasks should be
changed to 80386 TSSs. It is theoretically possible to mix 80286 and
80386 TSSs, but the benefits are slight and the problems are great. It
is recommended that all tasks in a 80386 software system have 80386
TSSs. It is not necessary to change the 80286 object modules
themselves; TSSs are usually constructed by the operating system, by
the loader , or by the system builder . Refer to
Chapter 16
for further
discussion of the interface between 16-bit and 32-bit code.